Figure 1; Mindle Beach, Darwin, the lovely warm sea is full of things that want to eat you.

We sat on cheap plastic deck chairs, hazy clouds thankfully obscuring the worst of the tropical Australian sun.It was still warm though, as even the breeze from the nearby river was moist and clammy and smelled of damp vegetation. Behind us stretched hundreds of square kilometres of reedy marsh and grass land, ahead of us were mangrove mud flatsfringing a turbid log strewn river. Aside from the chairs and awning, the only sign of human habitation was a large tree house. Not a child’s tree house, but literally a family home, ten meters up a tree. I wondered idly why the local family would go to such trouble when there was so much flat land available. The land itself felt like some primal beast, snoozing in the sun, heavy and ancient. A short distance away, two Americans, evidently soldiers on leave, talked at each other with forced bravado. They talked about how fast they could clean and operate an automatic rifle, but I could still detect the nerves. I didn’t blame them, we all knew what lived here, what we had come to see. We were all a little scared and excited.

Figure 2: Don’t worry, the flimsy red and white tape will hold back any dangerous animals!

There is a part of the human brain which remembers being a tiny rodent like thing, hiding up trees and in holes, away from the sharp teeth and claws of the terrible lizards. The dinosaurs are long gone, blown from the Earth like dust, by a chance encounter with a city sized chunk of space rock, and the volcanic fury of the restless Earth. But not all of the archosaur lineage disappeared in the extinction at the end of the Cretaceous period, some 65 million years ago. Some archosaurs survived and prospered and it was two of these examples we had come to see.

It was time. Summoned by the chatty and disarmingly relaxed boat captain, we trotted to the gang plank and headed down to the boat. Ahead came gasps and nervous giggles, there, not 5 meters from where we had been sat, was an enormous crocodile. It wallowed in the shallow muddy water by the pontoon boat, dead still and silent. We looked at it, and it looked right back.

“That’s Jim” said the captain’s son, no more than 15 years old, “He likes to wait by the boat to get fed early”.

Figure 3: “Jim” lunging for a snack

More nervous giggles, surely this was not a real croc, just sat, waiting, right? Sure, it was very lifelike, I marvelled at how realistic the skin texture was, how subtle the tail movements, it even had moist eyes that blinked! The captain and his son both kept insisting that Jim was real, despite our protestations. Then Jim opened his jaws and from that gaping, tooth lined, saliva strung maw came the unmistakable stench of rotting meat. Jim was most certainly real and very much alive. He followed us, silently and implacably, as the worryingly low pontoon boat pulled out into the river. Alarmingly, the ‘logs’ we had spied earlier also all turned and swam slowly to the boat. Out in the river, surrounded by hungry crocodiles, the boat felt very small and flimsy.

It’s a startling experience to be a couple of feet away from a creature large and powerful enough to eat you. A creature whose head alone, is nearly as long as you are tall, whose jaws are powerful enough to snap you in half. It’s frightening and exhilarating all at once. It became even more exhilarating when the captain enticed Jim to rear out of the water, chasing a lump of meat on a stick. Then suddenly, Jim and the crowd of smaller crocs seemed to become apprehensive, sliding back into the water and vanishing. “I guess Brutus is coming” said the Captain cheerfully.

Figure 4: “Brutus” was too big to fit in a single photo

Brutus arrived with perfect stealth, in a moment the river was suddenly croc free, then something huge and primal floated silently up beside the boat. Brutus was the king of the river, over 5 meters long, weighing close to a ton and over a hundred years old. Brutus’ age was determined by close examination, under heavy sedation, when he was captured after a killing spree at the local cattle farm. One of his eyes and front claws is torn and damaged from a long-ago fight, but still he rules the river with an iron jaw. Once again, the captain enticed Brutus with meat to leap from the water. This time the leap took him up all the way to his lower legs. He was huge, easily big enough to land on the boat and crush it. The Captain assured us that this almost never happened. It turns out that even a beast like Brutus prefers an easy meal of meat on a stick, rather than tough stringy humans.

Figure 5: Young adult female, suspected to be carrying Brutus’ eggs due to him giving her preference for the meat morsels we gave them

As Brutus prepared for another spectacular leap, a shrill cry came from the sky above and a black feathered blur snatched the meat from the stick and the jaws of the croc. Swirling about in a churning cloud of talons, beaks and wings were dozens of kites. Birds are another surviving lineage of the archosaur dynasty, literally dinosaurs that took to the air as their land based relatives succumbed to extinction. Red kites are a common sight here in Oxfordshire, UK, but these ones were a different breed altogether. The large black kites harassed the boat until the Captain threw meat into the air which they then caught and fought over with spectacular aerial acrobatics. The black kites looked ragged, rangy, dangerous and had no fear of trying to mug the boat or crocs. On the edge of the milling swarm, golden Whistling Kites swooped gracefully, avoiding the black kites and crocodiles to snatch meat morsels and fish from the water, diving with an almost musical whistling call.

We saw not only crocodiles and kites but a variety of birds, fish, and other reptiles in the fertile mud banks that line the river. Mud skippers and red crabs dug homes in the mud, and brightly coloured venomous snakes slithered along the water’s edge. Eventually, exhausted, we returned to shore and to the long drive back to Darwin.

Figure 6: Presented without comment

We passed a bill board by the road warning that rising sea levels due to climate change would flood this whole area. We began to discuss why crocs, birds, and snakes etc survived the Cretaceous extinction while other organisms did not. While many species will inevitably perish in the face of anthropogenic climate change, I have no doubt that the creatures we saw on that day will find a way to adapt, survive, and prosper as they did once before, 65 million years ago. The question that remains, then, is will humans be so resilient?